由于Base64错误，无法将图像上传到数据库

我正在遵循有关如何将图像上载到数据库然后进行检索的教程。我的WCF服务运行正常，它具有将数据插入数据库的功能，如下所示：

public bool CreateTeam(string userId, string teamId, string name, string coach, byte[] photo)
    {
        string query = "INSERT INTO t" + userId + "(Id, Name, Coach, Photo) VALUES (@id, @name, @coach, @photo)";

        try
        {
            SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["TeamsConnectionString"].ConnectionString);
            SqlCommand command = new SqlCommand(query, connection);

            connection.Open();
            command.Parameters.AddWithValue("@id", teamId);
            command.Parameters.AddWithValue("@name", name);
            command.Parameters.AddWithValue("@coach", coach);
            command.Parameters.AddWithValue("@photo", photo);
            command.ExecuteNonQuery();
            connection.Close();

            return true;
        }

        catch (Exception ex)
        {
            Console.WriteLine("" + ex.Message);

            return false;
        }
    }

在我的控制器中，我有一个对WCF服务的引用，并有一个HttpPostedFileBase来获取上传的文件，如下所示：

[HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create(Team team)
    {
        if (ModelState.IsValid)
        {
            HttpPostedFileBase photo = Request.Files["Photo"];

            TeamsService.ServiceClient client = new TeamsService.ServiceClient();
            client.Open();

            if (client.CreateTeam(Session["DynamixSessionId"].ToString(), team.Id, team.Name, team.Coach, ConvertToBytes(photo)))
            {
                client.Close();

                return RedirectToAction("Index", "Teams");
            }

            else
            {
                return View();
            }
        }

        return View();
    }

该ConvertToBytes功能概述如下：

public byte[] ConvertToBytes(HttpPostedFileBase file)
    {
        byte[] fileBytes = null;

        BinaryReader reader = new BinaryReader(file.InputStream);
        fileBytes = reader.ReadBytes((int)file.ContentLength);

        return fileBytes;
    }

我的Team模型是这样的：

[Key]
    [Required(AllowEmptyStrings = false, ErrorMessage = "This cannot be empty")]
    public string Id { get; set; }

    [Required(AllowEmptyStrings = false, ErrorMessage = "This cannot be empty")]
    public string Name { get; set; }

    [Required(AllowEmptyStrings = false, ErrorMessage = "This cannot be empty")]
    public string Coach { get; set; }

    public byte[] Photo { get; set; }

    public HttpPostedFileBase File { get; set; }

在我的视图中，我有一个表单，其enctype属性如下：

@using (Html.BeginForm("Create", "Teams", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    @Html.AntiForgeryToken() 
        <div class="form-horizontal">
                @Html.ValidationSummary(true, "", new { @class = "text-danger" })
                <div class="form-group">
                    @Html.LabelFor(model => model.Id, htmlAttributes: new { @class = "control-label col-md-2" })
                    <div class="col-md-10">
                        @Html.EditorFor(model => model.Id, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(model => model.Id, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
                    <div class="col-md-10">
                        @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    @Html.LabelFor(model => model.Coach, htmlAttributes: new { @class = "control-label col-md-2" })
                    <div class="col-md-10">
                        @Html.EditorFor(model => model.Coach, new { htmlAttributes = new { @class = "form-control" } })
                        @Html.ValidationMessageFor(model => model.Coach, "", new { @class = "text-danger" })
                    </div>
                </div>

                <div class="form-group">
                    <input type="file" name="Photo" id="Photo" />
                </div>
            </div>
}

当我单击“提交”按钮时，其他字段将正确插入，并且可以从我的SQL Server数据库中看到它们。一旦添加我的Photo字段（类型为varbinary），就会出现以下错误：

输入内容不是有效的Base-64字符串，因为它包含非Base 64字符，两个以上的填充字符或填充字符中的非法字符。

为什么会出现此错误？关于如何解决错误的任何建议？